Strange streak discussion: 2004 Dec 7 APOD

Comments and questions about the APOD on the main view screen.
Graeme Hird
Asternaut
Posts: 1
Joined: Tue Dec 07, 2004 6:52 am

Post by Graeme Hird » Tue Dec 07, 2004 8:31 am

I'm convinced we are indeed seeing a capture of an impact from a meteorite. I've enlarged the image from around the light post and believe there is a bow wave or shock wave from a meteorite captured there.

Go to http://www.scenebyhird.com/SinglePhotos/impact.jpg.

I think the shock wave from the meteorite has blown the light globe without the light itself having been struck by the object. You can see the disruption to the shock wave in the image I've enlarged.

(It can't be a shadow from a contrail - the sun is low in the sky to the right of the image, not up to the left.)

scosol

Post by scosol » Tue Dec 07, 2004 8:32 am

wow- the first thing i notice is that the streak is not straight- it's got an arc to it which would imply that something is either being ejected from or landing on the light pole-
but in some spots it doesn't seem to be totally concurrent, as I would expect from a flying object's arc

but yeah- any "thing" hitting the lamp, or being ejected from an exploding lamp, should have caused some physical damage.

looking at the 3 frames in sequence you can see what looks like a physical deflection of the portion of the tree right to the left of the pole
(it appears to "blow" in the proper direction that would indicate some force being emitted from the lamp- towards the camera and to the left) i dont see the same sort of physical movement of any of the other trees in the local area

while it's possible, normal lightning creating an ionized trail that straight would be a very rare occurence-
i'm betting either ball lightning, or an internal failure in the lamp causing the flash and vapor, and perhaps the initial flash of energy was focused in to a ring by the lens of the lamp and the trail shown is its imprint on the film

my problem with that theory is that i would think that any energy emitted would likely overexpose the film/ccd- causing a brighter streak, not a darker streak

so- ya got me!
any word on whether this was digital or film?

ivar

Lightning

Post by ivar » Tue Dec 07, 2004 8:33 am

It seems to be that lightning hit the lamppost, and yes I do think it hit the lightpole. I saw something similar to this when a lightning bolt hit a building, a big flame shot up from the building but when inspecting it, no damage was found, probably because it was grounded. If the flame or flash shot out to the right of the image, then the shadow could be of the lamp post itself.

Yet Yet another guest

Perhaps there is more than one thing going on

Post by Yet Yet another guest » Tue Dec 07, 2004 8:35 am

I am thinking that the smoke might be from a completely different source such as a mored boat. The flash i reflection on the water from a break in the clouds. The dark line being straight could be man made such as a plane since pased by or some atmospheric consequence of the present conditions.

Nice picture though,

clear skies

Dave Sanders

Strange streak and flash

Post by Dave Sanders » Tue Dec 07, 2004 8:35 am

How about this explanation.

The streak is caused by a small meteorite. The apparently straight line lends credence to this.

The darkness of the streak is caused by light refraction. As a meteorite passes through through the air is creates a tunnel of near vacuum surrounded by a tube of compressed air. These layers of different air densities would cause background light passing across the tube/tunnel to be bent and sent in other directions, the camera would then see a line of slightly darker sky. This tunnel would collapse very quickly of course.

The flash is caused by the meteorite striking the water directly behind the light pole and exploding.

Since it is still daylight (or at least - dusk), there is too much ambient light around for the normal meteorite flash to be seen.

RRK

Strange Streak

Post by RRK » Tue Dec 07, 2004 8:39 am

Where's the perspective? I think that it is important to note the uniformity of the thickness of this object. If the shadow, lightning, meteor, laser or contrail theories are feasible then the thickness of the object in the foreground, being only hundreds of yards away, should be much wider than the object in the background, a mile to two miles or more away extending to the distant clouds and diminishing in perspective with regard to distance. The object must be parallel to the film or image, directly on the film, lens or extending laterally from the lamppost ending in mid-air.

ukuleledre

dark streak

Post by ukuleledre » Tue Dec 07, 2004 8:41 am

i'm tellin' you, it's a sailboat mast. i don't have a clue as to what event the camera recorded, but the vertical structure in question is the mast of a sailboat.

mark seibold

questioned shadow image in clouds in todays APOD Dec 7 2004

Post by mark seibold » Tue Dec 07, 2004 8:44 am

:arrow: I would agree with several other posts that this appears as a shadow from a contrail above the lower cloud deck. At least that is my first impression. Being an amateur astronomer for over 35 years and teaching recently, I have done thousand of hours of sky observations from the Pacific Northwest US, a cross continental road trip - 10,000 solo miles driven while I provided solar sidewalk astronomy- see:

http://www.infobtainers.com/seibold/sol ... ourney.htm

and 3 months in the Fiji Islands where the south Pacific produces some very strange sky phenomena like meteors skipping off the atmosphere. The local natives told me that they always skip like this. I have seen many sky phenomena. This questioned photo appears as a shadow more than anything else.

-Mark
[/b]

Akihiro

Post by Akihiro » Tue Dec 07, 2004 8:45 am

Maybe the arc of the shadow (or whatever it is) can be explain by the refraction of light. :lol:

Guest

Re: dark streak

Post by Guest » Tue Dec 07, 2004 8:48 am

ukuleledre wrote:the flash at the end of the streak isn't near a light pole - that's a ship's mast. look close. you will find it is true.

sorry to all the exploding bulb theorists. :cry:
Many ships masts have lights as well so don't throw that out yet...

ukuleledre

dark streak

Post by ukuleledre » Tue Dec 07, 2004 8:59 am

the sun is too low for the flash to be reflected or refracted sunlight. the sun is also too low for the streak to be a contrail shadow *though i will readily admit it looks EXACTLY like a contrail shadow*. the sun's in the wrong place, though.

find the owner of that boat. see what he or she has to say about explosions.

was the camera set up indoors or out? interior window reflection has been the source of some of the greatest ufo photos ever. just a thought.

DC

Post by DC » Tue Dec 07, 2004 8:59 am

The linked newspaper article says it is a light pole, not a ship's mast.

The reflection in the water is interesting. The shape is like a circle with a forward slash through it. The diameter of the circle exactly coincides with the width of the dark streak in the sky. In other words, the corridor formed by the dark streak, if extended, would exactly contain the circular reflection in the water. The bright spot is in the lower part of the corridor. The forward slash part of the reflection does not quite intersect the corridor at 90 degrees, but is tilted slightly more towards vertical.

Grant Petersen

dark rainbow photos

Post by Grant Petersen » Tue Dec 07, 2004 9:00 am

I have two of these: Taken in east Va two months ago.
They were clearly visible dark arcs in the sky, one fainter echoing the other and show up well in the photos. They lasted 2 to 5 minutes.
There were contrails (thats what I was taking photos of) but they did not appear to run parallel to these and the shade runs right to the horizon without narrowing the way a rainbow does.
Nice sunny sunny day.

g dot p dot petersen at clear d0t net do4 nz

Astro

Post by Astro » Tue Dec 07, 2004 9:11 am

I'm sure it's the phenomenon known as "Flying Rods".
An insect flying by in front of the camera.

Image

ukuleledre

dark streak

Post by ukuleledre » Tue Dec 07, 2004 9:11 am

i'm not aiming to be contradictory. the reporting newspaper doesn't have any more to go on than we do. i'm sure they said light pole because the photographer said light pole. there are clearly light poles on that pier, but the pole in question is not one of them. it is one of a series of irregularly spaced poles of differing heights with no visible light fixtures along a dock. in the before/after pics you can just make out the rigging.

Sky

Dark line in sky

Post by Sky » Tue Dec 07, 2004 9:14 am

If there was a jet and contrail in the sky, the contrail shadow explanation mentioned by other participants above, goes well with what I have witnessed several times from my work place. I asked a State Inspector, (with a degree in Engineering Physics), at work one day if he saw what I saw, a black line extending from the nose of an overhead jet to the horizon. He gave me the same shadow explanation as explained above. The shadow only last a few seconds though as the Sun's angle, and viewer's position, only allow a brief glimpse as the jet travels overhead. Nice photo catch. Happy Trails, Sky

OwegoNY

potential witnesses

Post by OwegoNY » Tue Dec 07, 2004 9:15 am

There are several potential other eye witnesses...

There appear to be at least three vehicles in the park/trees area to the lower left of the frame. The car parked by the water might have offered looks like it might have the better land view. There also appears to be some kind of watercraft near centerframe, maybe a tug? and another object to the left of it.

Also there are the nearby structures with windows.[/list]

Sharon

APOD

Post by Sharon » Tue Dec 07, 2004 9:16 am

Is it an anti-crepuscular ray?

I've seen those, particularly near sunset, and they look similar to this picture. The lighting conditions make me wonder whether this picture was taken near to sunset.

Yet Yet another guest

Post by Yet Yet another guest » Tue Dec 07, 2004 9:21 am

The flash seems to have the same colour properties as the ambient glow all over the bay?

We could be looking at a more disturbed section of the water or the light source may not be the sun?

The smoke is not related and seems to be something entirely different?

I agree with others that this is a contrail based line that runs across the sky.

Clear skies

rhess

Strange Streak & Flash

Post by rhess » Tue Dec 07, 2004 9:25 am

Dave Sanders (Posted: Tue Dec 07, 2004 8:35 am) is most probably right:
The streak is caused by a small meteorite. The apparently straight line lends credence to this.

The darkness of the streak is caused by light refraction. As a meteorite passes through through the air is creates a tunnel of near vacuum surrounded by a tube of compressed air. These layers of different air densities would cause background light passing across the tube/tunnel to be bent and sent in other directions, the camera would then see a line of slightly darker sky. This tunnel would collapse very quickly of course.

The flash is caused by the meteorite striking the water directly behind the light pole and exploding.

Since it is still daylight (or at least - dusk), there is too much ambient light around for the normal meteorite flash to be seen
- The burned out bulb (no damage to the post or bulb itself) is probably a pre-existing condition and simply coincidentally observed and noted.

- It is highly doubtful this is a contrail shadow because the photos were taken at 15 sec. intervals and there is no sign of the darkened line in the rest of the sequence.

David Batchelor

More thoughts

Post by David Batchelor » Tue Dec 07, 2004 9:26 am

First of all, as someone with some professional experience in meteorites, I have to agree that we can rule out that possibility. One of several reasons is that meteorites smaller than about ten meters would lose their "space velocity" (the high speed with which they orbit the Sun) coming through the atmosphere and be slowed to their terminal velocity (less than the speed of sound). At that speed, they would be falling almost straight down, and the dark streak is clearly not vertical. Meteorites from 10 meters to roughly 100 meters tend to be shattered by drag forces in the upper atmosphere, and only those larger than 100 meters or so reach the ground still traveling at space velocities. (Note: although I rule out meteorites, I'm not sure whether the argument would also rule out reentry of manmade orbital debris, whcih would move slower to begin with.)

Having said that, I don't know what I'm seeing here. Assuming the photographer is not pulling a hoax, is there a possibility someone else is pulling one on him and has messed with his picture?

Assuming that's not the case, let me throw out a few observations.

1. The camera takes digital pictures, so the various film explanations don't work.

2. The Sun is to the right of the picture, not behind the photographer. The bright towering cumulus cloud is illuminated from the right, as are the boats on the left and the building on the pier on the right. The broad bright area in the water is a reflection of the cumulus cloud, not direct sunlight. This angle makes the contrail argument a bit more difficult, but I'm not sure it eliminates it.

3. From the few pictures I remember of closeups of the base of lightning columns, I agree that the dark streak is too straight to be an ionization path from lightning, or the smoke left behind by lightning.

4. I have no personal knowledge of whether these types of lights can burn out, short, or rupture with a bright flash, but I doubt the dark streak is a shadow from light at the apparent flash. On magnification in Photoshop, the top edge of the dark streak is significantly above the top of the light fixture, and as others have mentioned, the streak doesn't widen or fade with distance from the pole, nor does the general light level decrease away from the pole.

5. The so-called smoke or light streak near the pole has two features I haven't seen discussed yet. There is a fainter streak, symetrical about a vertical axis, on the left side of the pole. Together these make a "V" shape whose apex is just above and to the left of the base of the pole. Also the nore prominent right streak is interrupted by a circular pattern which does seem to align with the dark streak. I could accept the circular pattern as lens flare from the apparent flash, but have a harder time accepting this explanation for the V shape. A condensation is a tempting thought, but I'm not convinced.

I can't eliminate bugs on the lens, the lamp being hit by something moving fast (just not a meteorite), the contrail/light burning out coincidence, or a hoax.

I hope someone can get the light fixture and lamp inspected and give us some more details on it.

[/img]

ukuleledre

dark streak

Post by ukuleledre » Tue Dec 07, 2004 9:27 am

previous posters seem to have determined that this photo was taken early in the morning. the photo certainly looks like morning. the sun is not yet up in this picture, so maybe crepuscular rays could be seen at that time.

however, crepuscular (and anticrepuscular) rays are rays. they radiate out of the sun (crepuscle) and seem to reconverge on a point opposite the sun (anticrepuscle). shadows also radiate out of the sun, which means that shadows on and around the earth are functionally parallel to sunlight. this is why the streak is not a contrail shadow or an anticrepuscular ray, as it is perpendicular to the (not yet present) sunlight.

btw, the direction of the sunlight and the angle of the sun below the horizon can be determined directly by observing the clouds in the photo.

rhess

Strange Streak & Flash

Post by rhess » Tue Dec 07, 2004 9:30 am

One other thing,

This is not a flash. It is a splash, backlit by sunlight late in the day.

tomasv.cz

Post by tomasv.cz » Tue Dec 07, 2004 9:31 am

Zoom it on and look at the diffused orange circle around the light centre.Rare jpg (or others) does not produce such a diffused shape.(compare to the other lights on the pict.)
To me it looks like using smudge tool in the Photoshop.

Douglas

GIMP

Post by Douglas » Tue Dec 07, 2004 9:33 am

Since nobody has posted this here yet, my try at making a good diff of the pictures: http://images.isja.org/images/strange_diff_pryde_01.png
and here a quick preview:
Image
(this is GIMPs "Extract Grain" layer-mode, of the middle picture against (50% of before + 50% of after), and increased contrast)

I don't want to interpret this, just ask everyone who is going to post:
  • Please read the other posts
    Don't repeat without giving new insights
    If you post a new theory, please be sure to address any already posted points which would make your theory invalid
Thanks. From someone who actually _reads_ all those posts :)

--
Douglas <douglas at isja.org>